SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57e53710184b973117b26483f5360ae8ab25b378d4992f0e009cd50e48f44d9a' 
  AND token = 'f5pIEDsKeyEIobaNDX3w419o6xClXDOHKa2hWJrU5Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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