SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5264785ab546c509ac2d4db4d7e2cf36782ff1533ba2847ac89955887c5babbb' 
  AND token = 'blnASRasJ8GjTcrukBHtNhdb1keDVBtPvtqd1yOV6Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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