SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '51480559b7c43f6c0e866b80845a61cb57b1570e69285ff84c6bf447aa9adaf0' 
  AND token = 'vaa1Qf5zbTa+hzIdNjB38k5cFzkYpTulDNQIunLwrho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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