SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0856273537c8bddeea9f6ab24f3f08d44eb85bfecd79c712a00e2063faf651a' 
  AND token = 'MofWs9XpmNULzP0uwGUowHTlasCFcQojDU5ZOX+IYh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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