SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cebb3f464d3f55e8eb0a4c98296eaadf9796d08096a7edf6d1bb19a56831190f' 
  AND token = 'DAI05m22/Z2kYBmQekl9V9XJB21Ej1iJOul1C6XotzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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