SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e82615c96d6d94e89508ec97dce7fdf9d71734fef481e1adc5356d13bf11398c' 
  AND token = 'yEwER7pYIbznV5R6uMJ7qkIyKcyGr4afcGBVaSutpRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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