SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aad78cb3f9090cb1b0170e829437aed51a5e22e70354af686cb726e86b75e93f' 
  AND token = 'eE4eZs+LKQpjC8c9jkQOHgo/vhkVfqrffVw1uZpVrOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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