SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2241ce8b8eb4e8513cea49db7dd1fb1b67911b3a1b18326ae47dcb33adc7090a' 
  AND token = 'SALjbotlYRGnT8qUtkSpbhbQ4J75/MJvI2oeyvzeICU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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