SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a38bba163dddc3fa32f43f82e9f2b9f044b24b8853dc167f97222914d4c59aaa' 
  AND token = '5Vief+VvgfDP8b7vEwP8I2hGVCFqdM0KxqGJlMxvX3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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