SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2aea6f039cb245e2aa2058fef42d64f1b4a7eb8ae035dadd3cb8b17032794d1' 
  AND token = '4yNaOLFMzLC6wYLEmxeogMV6jQSoHzuGuX/gpAg5CIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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