SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '741f204072388bab936b4a59d2b92767e39e55e1f45de680a908b8b479feab66' 
  AND token = 'yaJ5+OI58BOfLoWWrK/Su/QFQgdVXOnQGJzuxDSSD9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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