SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c5d62233fb7535998d02f951662da77d6f9d54cc8c917f2a53b932ae742adf5' 
  AND token = 'OMb3ZSLM/eqhkYJAU+M8K9ysIlUPLGmr+0XOP90NJZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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