SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1890d81b9bd735bbda0633078525ba78188b391d69fc18471c7d042d837f9b8c' 
  AND token = 'o0ZhBl9FGhs+Aslm3lziKXi+sEblsGsuOiRil4SQRp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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