SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ed9de1cdf42fabdaedae09fb13cfe4df626d2900ea2a1fcbb33ad5c688444b74' 
  AND token = 'KQtYAsEYHJqOzudUhj9jfUOiDth+4MiZbya33f/jLVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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