SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4627a4726cb94a84e0aa8e12e9a53ea983bd57f0556da4bfe493061311048349' 
  AND token = 'mQXbjdC9Rq66Xrdi5W7ZvryTKXOpCDXmw0ircse/+sQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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