SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31703ff02a7e8b432b028a6419835ba9c3f933ef93cac79c0608e0156af16282' 
  AND token = '5LyT/GCiYMIglXYONOhHJLcyYBdN99KTe2qBxjgBo5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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