SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '841a2aac9abca453eb04c632c268f2a8110e5ba3146b7b1a0ba7d5bc60c81b96' 
  AND token = 'lyrinh4JmSvQnJONcr0edFsVfe1YvmFKwUDcGVAieDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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