SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe33a2fe87eb598b739524de3f89832a37534e144345233b5794ddf101cf5198' 
  AND token = 'kvYMFlxF6NIxnG7OXcPh0TEyF6EmSaHqEJ8TjDPAe0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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