SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5033745da72a2b0346bf822b3ce22c14fa1498a344976f8bfc64515c1e0089e' 
  AND token = 'DPpadZwe9s/RD8gw3VD6TKGORW7gms86pdKoF0+PVFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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