SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6299d9c66be74ad20fe5c5873d8da354179a22aee45fa40ec9a25ccc7454260' 
  AND token = 'duDAVJ/JZAg5wFZVvXbiYmQKQPBMbM6bQbISEKzzLlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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