SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fe69a45fe11ea9e5ae171c322dd6f31b15eeee682a5f5fd67e818f040a22279' 
  AND token = 'd/U7YxnX0ujTsE86dNUFclOUgEXpub7uoHE+SDQOhl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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