SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5b0a92406e00ad47a0161a3efb787a981f06ee68528bdc8cae749b1e88dc025' 
  AND token = 'tvaIDTZydh+f5HzjXgaqVL1vDPjJ+aXjMcKf/Y9wgM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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