SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c38dfd57198f14295ca0c664caa6d7287ae2a814556c7b53faed09e08ffa35e' 
  AND token = 'ewPuhbS8uSYMcgtsg50osNDlntn9xfyqS6pd0fXr+0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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