SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf5544731678c7aa9c718681ee8385be34b59a5613ad26a2c7f5f01c855eddc' 
  AND token = 'Hxg9RscBMQ+zxuChzRYoYlT5Pfw8bQC9JQ/khtEwmpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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