SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c43cfef154edc943672bffd55cfa1c357707df0348120a810d68ab09b95cd921' 
  AND token = 'kS9885B+SoUE3ZxHHKBttkwmO7r6Bmw+N07d03fxwVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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