SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79e97756fc1788000f22ad60cf8a5712d4492ee1a253b8fa8f0fd917f03f85ec' 
  AND token = '7j8rQfr6YdcFhzCw0Q+pqMHhO0R+nhyrr5POW5MuJjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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