SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff29b152715340b132176d4ec4b98a977afc762b5eccaf6c162e31d40d3be2e4' 
  AND token = 'yXIXqcX4tpa4Yql/mPu1Z4ARvoEve6nV9g1QxyYKJNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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