SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2bd508235a49f564aa949fb74324444700f91c4d6b3942f8796c50a83af06123' 
  AND token = 'xvxG1f27xRMzp7rXqGzcBSdgGD2XsYPVpPFqgtLU1VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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