SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '47234abc67f052bced1d516ece9ec20f5be969c8b62380177681cf7073f73363' 
  AND token = 'a/eJJSkY/X7bKCjMsyxEeKjQ/uBIZPkP2y39YPFdY0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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