SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d0ace9a08fe73fb732af5b56ea5b69d7f93e01df510f484833e6130c6fa7eb3' 
  AND token = 'nSiB6uEXMSk/4mqenmOQSiBXL1nH2Y8nvFyQ77jpV/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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