SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d82493e5ba5128c7ff26cf73f287024da679bf1365952c00788e4236aefb40f' 
  AND token = 'S9RiP4COiOUBZt3QFqX/Uhf92czNmK5WvlrAY+STwZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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