SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4793ddcc53e92504c39baa539ff39bedb9dda26840ffb43d20f76d804f098066' 
  AND token = 'AIWKjIVzEEAUNC6riF9+Sp2IXl683lCI+knbxG0cE58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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