SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '627addc348044adc4b9339a76e5e8ddabc6957591585174571212b8b254f82cc' 
  AND token = 'VX0WrV86iScEXATb++r8dw18ULLFTzfd8IrbKH0F9JE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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