SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0fb54ed1bf166f928de20818b45564b10bb10e4261325595b6a633b5b8f2c708' 
  AND token = 'mRn6mL3d6ETkFy/zLbNhhteCJt/fCBTAXA01HeOvyKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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