SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baf62e5f83dc6cf504c80668fb2b49298bd314e5126bfc0c53053a45c1b9e348' 
  AND token = 'FXGQ+qTLmYdU/kHgRuY/Ufxe2v2VDvLy0QroEny6jOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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