SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97dcb952d419f25372f1c5e0f52abc8535263409a94f38fd456839b09c93a099' 
  AND token = 'n4+0AvgVZrUndlq7RbaJnfRpQGoHEhSckhW550mc+FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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