SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24501fd0255be3e8f43741897fbb530a85b536da27ad758bdbe7079be25218ed' 
  AND token = 'bL6khPzP2dG67HxdJUWfta6r7pZ4UBBpi6BHMmAPMAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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