SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd99fe7e7584573cb40cd16518f6e8d3b5f695693f26ec5cd68f9c0f6a34f0820' 
  AND token = 'EoOpKx5deEpg8gn3W2sADsXcM1KuRT+8uveclNTQYSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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