SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe61412732798ec15b8d09e071069e6953b64905afdbf074aab5472eeb27bdb4' 
  AND token = 'OM6CA7hn/hOERcraU8P1q/XUEFsBCT9emgi2kt8+LUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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