SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01ff738898bf516cea11a30d9529d4441fa617bc10a20702f0e79e0f31257128' 
  AND token = 'nQOEtKmB60Yo+qCPYKz+7aaqH3GjincJdTlBn51bLgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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