Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8bc9477931485023f0c7b22906a599d1d73ff8c3c158235083bd4c4e3a54ff0' 
  AND token = 'Nc+a+nf75bA8LQczjN7A3PuSQjhIIXflv7kaEMTxT2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}