SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbb38544c307b5390240361141eea845ee2edc48d1a080778f79918641835547' 
  AND token = 'du/3Cou7PF294ymQPKkfVYPXJz/HjtUUGDHYDDToxeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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