SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c21b564d596ea100211b1ae2108f2db3cc5b0ae74ff70eb11c03d21dd65f728' 
  AND token = 'IizfRs9sCa1AgFp6JLksCzvicgI9c6K+6EXq0/XmqfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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