SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b894d7404252effa9769854f1625464e7c83fff69a2dc04e5b5773700c3536d' 
  AND token = 'ymKf7gJxDf9g0roGTjxY8uot3sZptE82tnRBFrYG3T8=' 
  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"
    }
  }
}