SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8221e3a349fcb6ee85dd044fc2e3323f614171431cd2fd27c19298f48094abb8' 
  AND token = 'RxW6A8KnPUWKyDRnvdmlRreHvEY4V6vEEbbJUMRGN3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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