SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecc1b13fdcb842e03721fb0cd369b0697e252c55a93b76a5972012f0caadd47c' 
  AND token = 'z8c09PkHeFP6kewNecctg/2kZPrdKQX0K3+PTEGgKMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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