SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d536355fe5c2be2a8cd861646fba2ecabeedf2731eff9670b1a5a0ee61e6da9' 
  AND token = 'kQrx60m/fZmhZKHPoRFHs+OIalkHtnTBorLSgF+Y5Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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