SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f29290dd59b7a2648e698a38be9bad5e01f50c503287800698bb4b32c45b551f' 
  AND token = 'jAurv/oMyPe0TL68nEGVhWQbXQQgecrehid/lvDYraY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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