SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36059b0cb913719132b6478f16e0a7bafaa167750532da04e33d5b11cfed833d' 
  AND token = 'aO3u4wC+nPGe1JF2zJSrvKIOHZKzRqJL9OsNvtW3epE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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