SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc23416d1b4385d4341d6b358a6ee950d32ea0504a54b6899679e7d6a69830a1' 
  AND token = 'FNcU9SEBtWE3o5k0d7HyDok1l1V7hjZbh6Y85SuHxgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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