SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a2c2a5e73224b7001c39192fe30fb6a27be7198df623ae0eb64b2dd5869afef' 
  AND token = '2dHkFcROJ/O4uOBWD4kpMEvuRmd5uuHSWz/YLoLf+kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00157

JSON explain

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