SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bdcffe0a538323e44d43495b77dd5e64f7bf254a0abcfeb3f66693f2101db4d' 
  AND token = 'MQ2ZfZn8WfLylCIvibhvWCOc+eIM/qPDw9i8/A1ZgKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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