SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e593f2b984ebce217682e43e7ef050668dfd8dddf1059c31f4b49849a6ad37f' 
  AND token = '8owML9hmpVqFZZeB13hM3b3wqP/qYJUDH8nBw0q5dbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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