SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '816df388bc8df3eef7b25a8fa97fba078b6718fe6db3ee7f3a7000cbaa4e6f26' 
  AND token = 'dlQZUSa89Z8izHLcuw4VKYqO0Q8kiCBOAcBMjskK2aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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