SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff9ebf58cc8c01b8c9357dad0547e2239cfb64d09ffb39c878a59630d77868bd' 
  AND token = '/pvWVdjNYV7iCCR2SYyq9njcPQJsxmTmAEfYZHc1lKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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