SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19844b9c14cf6f19d675c92624cf8d66569f1066898cf56c3550e164caa31fbc' 
  AND token = '+BS5PGak7KM2A1D/dKCrzUOqI0WOYCowBlXuxmasZT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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