SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd88c7147e7cf3b43ff6e399d7719d3331339265d0c23184c144138276dc54a' 
  AND token = 'jrkuAJv+gf5vQIV5SSLLHqpE+w+d+hGa8oT9wKgTEKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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