SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3cc648190d8f7358c4df4f6b91264a1e884a3f84139f3eb58eb55e6551be8e98' 
  AND token = 'lM7pdbtJo6Ygxiohc9DvVR7qc3vU+KTN+xH2HWBjnmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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