SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5c111f79f225b05d467ab8e9d35a5444c336203b15959b652b4cfd993070dc28' 
  AND token = 'a2Vh8Wa4k9tDBo4N2LWFsPQs1ZDynTgfOZjJ33uJAAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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