SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a31ca24bb72e29264ad265df2768bb4ce7706051675573c8a3bc03d4ad7d8e8' 
  AND token = '+zVKHPxfONDHjNCRZqZJzzYSbZ0lr4BM0+T4Z6cw+do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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