SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcf783756bc5598d6bad1bacf87708f4e6ee3cfaae524d58c65eb4efe106c6b2' 
  AND token = 'nUp607zL2U1oxrwnWTULOrBJb/xOBKD4dIUd9UVovKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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