SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c57e087de904307f770d0e09ea8700129cb4905847ab3460761a0a2c82a0f8f' 
  AND token = 'OcfhDLefyxc6A2yUqrMvZlGmyQyerPJpgXD6k7DRHak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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