SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491ea4ae7a8e23fbf2696568c4357111d362ef922259b3f904b797f6455fdd75' 
  AND token = 'Qjos0mUbzys8YKRCR88Oz/eJCy2hXYh6VvEjhvuGy9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}