SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1a988a8ad82b4aa9afd52209354bc21bc9241b0fa13f1bd5a647d9c77b42324' 
  AND token = 'lJEO6pnBqZZXHQR1tCWO5Z/98/gi/UUEI+B9phRgzwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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