SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3055c9f9507a3319c4a561fd470a20eac9c28d4651f452b7bcd52e2b5b82ff15' 
  AND token = '7uUzVRmuovtNipeB5iVQrzv5Q7vhjA9JmFkvbSgXGRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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