SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce8b46324819dc65cb1541f3cf8e3a7a1023006f67339a67b93ce5005dbdd935' 
  AND token = 'lkH2ix+r7Y0jkrozhTrbOJXgyEzz3adwF+QMpsm8vZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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