SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3460fd4c02d797e7efc774f762718d63e35a4d9428c62e993b5f716743f03ed5' 
  AND token = 'MG6oH1sF4MzsSBgcL6wzzlPGMN9uZatY/+JCKGHJnHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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