SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f64d53c93658d79020b2dac9246f70553ba9d08874590defc53cf9b5f57eb820' 
  AND token = '0uvq+ttv3RkfNekgWGx2yesx2U6HKshXu5je2i13sG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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