SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15aeffcb3f8458ddab7a33032238f2e91c589c6013a50d6f8b615109fe979614' 
  AND token = 'HX6Ctt9pJXAclklrLwTBg4rpZfOof+/Y2SpoT0eF4Fk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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