SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '011eb45ff5bb7cea5429380f21d4886d4c5fe429604e55107ffe3f086522985d' 
  AND token = 'zzlnErBh8OHFrxMrKtl175P2B7v971kIYSFZqwKOtSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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