SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bf54f2ecbe17d897bced402b60a3bfe846df399812ea279a86d7c5ec4d6e09c' 
  AND token = 'QLuIqNbGBxmZvF/dHh6L6nZzblhJqnHunMHFHXvhQAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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