SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '286908a927bf44997b9a56c0c0eabb0e4c044ec9389dab66d03f29f9e86742ab' 
  AND token = 'ZzRXMeYGzndkdwgU9YbuHEMhUAY2kCoEakxd1qZqUfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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