SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5ed8f417764e4e29c3d40092b04914e063451bdcb3b1ac6fe60a6eeae85a055' 
  AND token = 'oImgxHUQfpb8zywYltO8ZYtxWFZQW05zkNgKBSPxhvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}