SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6249227e90a3d97d0149a07d561e99ac88bd14e62466efee248329ee7db7a038' 
  AND token = 'wMFlGVD3YmCrMbWNL+6PhOfKjfguuWjVP7is+ISU3QI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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