SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b35fcf268e6cfb39b59b435696dce4c0aa7b7fe73c982855f225d7cf5e044f' 
  AND token = 'naujyC3ELyQBqprOIHxVBU9tZw3egMSPEWmPGStdYXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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