SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ad26c6f5c6f7f3517856ed8a1dac8a0d40684fa682549e4183b67bb7be4a2ed' 
  AND token = 'mYx/LngU0+UPt8QRjFWUxHtDH/wlnSfVuSHVymDzaks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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