SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c6e45356fcbaa62d6160b9f1a11ffbfb94a28eba9a296da693afa21cafc649f' 
  AND token = 'avHp0zAD5y2NXKc9xl1CSsvlkWO5iwuYbHktwOLcsLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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