SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ab2434867469f50f63d3ace4f3b52d23c1253577a4bafb6a4a460f7b9e9f8da' 
  AND token = 'XppZpngcc8Ii7BecJvGgp9xgVk0GTBgyZ7G9w1hqVJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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