SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2503d5d28f1e87a38ca2866cd8454e6647c807423b6ff67782b8a3166bdcaf5' 
  AND token = 'jtMFWwFnkTDhB3RI91Pxf/XbpzNORBfLEiJf4YMHuxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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