SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bc3f6d0269e168e93a34ef31be34c1278ba74d1f7bd990a4580832826d8fce8' 
  AND token = 'rVkxwdP0zj9zh9BRP9Qvwtgw5YNQgAuoLOKJHGzrmG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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