SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4a2ac448677bbbf7955bf8726217598dcfa576873b89587d5536bf831ad4fbc' 
  AND token = 'w3B99nszJYJ9NSzHYOYvCkDCkGQNKi8oZB4EKGNIH4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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