SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b7073d4d2365b46cb46e825004b9b5f38a1b007c00aad3d4428fad437b50698' 
  AND token = 'LfnNT8urxGj2UbGD9kH1OXmV5Q+DvyBIez7Tq6ga/FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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