SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f83fd87ad3734806130bba86172f7f4f473a469870441f8cef272b9b70eb6296' 
  AND token = 'J5K0Fbx3m8VbJhuFWR1YdiLi5Gl3kFpRbzWhFOm9r+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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