SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37a4f70afbd70fadcec714fde07fb6740766c7f8bfdbfcf9a5e692b61637f1be' 
  AND token = 'eeg6uMw0ZG0GXgkcrhSaogig5S7GKRsycZw5eDB0FXg=' 
  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"
    }
  }
}