SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b2e0936864eee76ed0355827fc555c1abf67827232ef743bdc7a9d1a637cc67' 
  AND token = 'pX9D8XdeJd9X9rRBX7Vy7jh9QFRaE7O7ii8aUZ6EqEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}