SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f373dc913874efc5ac4373f186e89517a799ecb0b36a8e389deea1656f93d17e' 
  AND token = 'NsM152YbJjrj4Mol/sYDp2U6atZE/6/EvzQDal8qOXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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