SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cab28c97aaff945bda310de2fe40852d25ab46f7b5c7028109edb7d5d7ddd674' 
  AND token = '5UY8mOH48jNSnXaxiDp4lWRAnDA8dcdjG7ALO+Yjmq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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