SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f368b37e1dadbf625193559cf826e52740580145eb5c8ddc61577d11256804c' 
  AND token = 'J61jK3XFmlDAM5Ucfuxkw5s0GWwgIowi0Err0sYQQJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}