SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbc2aec4602bb521e535b34774e6d2659674cb01255935aeb8a823370bf166cd' 
  AND token = 'm3yHigH8udIDVEglnjSrWXxsqNCtwU7TW7hKQvngRrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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