SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d1aded36537f1b5ed4e4f720358b96f043965cbf184ff0fa9e2cf832969f373' 
  AND token = 'EyGUysaJAMrw/CUKAHtPZse/jCwCLjlyUITW4+frzPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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