SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3462c493a7139d98cb602080d5ae82fe92e8034a3d3bdb6924ec2b856b10ee94' 
  AND token = 'mEvoSTpYuBYzAZZ5EGEtQlQgP4aGaWiYzvR8loDNuiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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