SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952278c629c5ba00097befa19808a5bc03378d84cb4ca1ba8fecb0ff0ab83981' 
  AND token = 'FYCrwEnbwX5rp1q5b188csZj+mMUI33id5CYQHe9apo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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