SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12cb792a4b77a73f164704798a85d3c948db632df5f15d9b11b002e64d2adebd' 
  AND token = '/YrYWrwDLaKgCVabp4wQq9IMUUoX8ukwV2pSGGAmJ1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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