SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb1acf1e6484cc006af54604769ea1a0d881b6e0463dfed410e048f9df9d6878' 
  AND token = 'Mjz/IwtfEbf4p6HtInMW/f2DgviW+srrVU+az1Wp34Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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