SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58f054b75fcaa9cf99675f1d7822b822cd7b45381fee66f037e8f50a0dddd625' 
  AND token = 'TR6aQWUHFQgYTr8RFEd7FCckBsySRTd0nCwPuw/eXZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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