SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8046eb36e0e83e43e6be060763a1d9ee21c3f672bae371db97ca549d99434c25' 
  AND token = 'pNtCSYU7MHQtadUufsg3nk0Z4f1zcfBNlu30qYokMVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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