SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a99401d8b026fbefbb060c9ceaa58851a431c4155d42ef9a11cbde0fc68b6cab' 
  AND token = 'jWjyrYWkvNPHCOJCJbTcrjqUpmIHQ8enp3bUsGjpGFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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