SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70f8840e3ebc86f81945589cc6724da53128f88a60e47074fd000b2c157752a9' 
  AND token = '8YKRvlaXPY2ePlYu366pvUeBgYto9OszGZzVS3ZsQVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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