SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5471cb9bd1ccebdedc39dd820e546e8a54f02eb57eafc7bb4ce92f6edaef807' 
  AND token = 'tPQMtlczDork5N1bA9+F5gNNNI/JsQizwCdzHmxcvqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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