SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d0b93b57e550d2b648c7b43be3b418f6ef16581eb5213a971e7086567cc0584' 
  AND token = '4RNvLVOB33LunXENGYKxmSgwDOGZ+9BUGMC8AhtXrg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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